VOLTAIC ELECTRICITY. 55 



uniform in results, and the oxygen and hydrogen more equable 

 in proportion to each other. 



If the acid were very strong a remarkable disappearance of 

 oxygen took place : thus a solution of two measures of strong oil 

 of vitriol with one of water gave 42 volume of hydrogen, with 

 but 12 of oxygen, which favored the formation of oxy- water, 

 which M. Theynard has shown to be occasioned by the presence 

 of acid. 



When solutions of potassa, or soda, or sulphate of magnesia, 

 or sulphate of soda, were acted upon by the electric current, 

 just as much oxygen and hydrogen were evolved from them as 

 from the dilute sulphuric acid with which they were compared. 

 When a solution of ammonia, rendered a better conductor by 

 sulphate of ammonia, or a solution of subcarbonate of potassa, 

 was experimented with, the hydrogen evolved was in the same 

 quantity as that set free from the diluted sulphuric acid, with 

 which they were compared. Hence changes in the nature of the 

 solutions do not alter the constancy of the electrolytic action 

 upon water. 



The learned Professor concludes that the investigation he 

 has made sufficiently establishes the extraordinary principle, 

 with respect to water, that when subjected to the influence of 

 the electric current, a quantity of it is decomposed, exactly pro- 

 portionate to the quantity of electricity which has passed, not- 

 withstanding the thousand variations in the conditions and 

 circumstances under which at the time it may be placed. 



The learned Professor in another part remarks, that he consi- 

 ders it established by an irresistible mass of evidence, that the 

 chemical power of a current of electricity is in direct proportion 

 to the absolute quantity of electricity which passes. 



The inferences to be drawn from the great variety of experi- 

 ments described by Professor Faraday, in his interesting re- 

 searches on this subject, are That in the bodies submitted to 

 electro-chemical decomposition, where they contain in their com- 

 position oxygen and hydrogen, as water, or acidulated solutions, 



